For evaluation on UCF101, we follow the test protocol of [1]}: We sample 10 clips from each test video at a uniform time interval, and for each sampled clip, we take three equidistant spatial crops, resulting in a total of 30 views. We use each of the 30 views as input to our visual CNN and average the prediction scores from all 30 views to obtain the final prediction result.
For evaluation on ESC-50 [2]}, we extract 10 equally spaced 2-second clips from each test audio sample.
We use each of 10 clips as input to our audio CNN and average the prediction scores to obtain the final prediction result.
For evaluation on Charades and Kinetics-Sounds, we use three audio-visual sequences with different spatial crops from a test video and max-pool/average the prediction scores from each sequence, respectively.
